In medical technology, it may be necessary to transfer a substance from a first container, for example a container, a vial or an IV bag, to a second container, for example a vial or an IV bag for dissolution or suspension and possibly the withdraw of the dissolved or suspended material back into one of the containers or to a fluid delivery device, such as a syringe.
Drugs intended for parenteral administration are typically stored in a sealed container either as a dry powder, liquid concentrate, suspension, or as a solution. The contents of the container may also be immediately used with a physiological solution prior to administration in a similar manner to a dry powder drug. The physiological solution can be provided via a pre-filled syringe or vial, IV bag, or other medicinal vessel.
Sealed containers typically fall into one of three categories. The first type is a vial or a glass bottle closed by a rubber stopper which can be penetrated by a puncturing element, and which is self-closing upon withdrawal of the puncturing device. Such a vial or glass bottle can contain a single dose or a multiple dose of a drug. The drug contained in such a vial can be under reduced pressure. The second type of container is an ampoule whose top portion is broken off enabling access to its contents. The third type is an IV bag provided with a sample port for accessing its contents. The sample port can be of the pre-slit septum type or may require puncturing.
Typically, a transfer device with a piercing element is inserted into the rubber or other closures, respectively, providing communication between the two containers. The transfer of the fluid may be assisted by the fact that there is a vacuum in the inside of the container containing the substance to be dissolved or diluted. Other flow channels may be present and may be routed through the piercing members, to facilitate pressure compensation between the two containers, if there is no vacuum in the container or if the user does not correctly assemble the containers with the transfer device. The transfer of the fluid typically takes place with the fluid-containing container located above the container with the substance to be dissolved or suspended, so that the fluid can enter with gravitational assistance. Unfortunately, conventional transfer devices fall short of providing simple fluid transfer, for a variety of reasons, some of which include improper use of the device, loss of vacuum in the drug-containing vessel, exposure to vapors created by the rapid equilibration of pressure, etc.
Regardless of the manner in which a drug is stored, there is a continuous need to transfer fluid under sterile conditions before its administration to a patient. When a prior dilution of a drug is required, the process requires at least two fluid transfers. The problem of ensuring proper fluid transfer under aseptic conditions and without the accidental release of aerosols associated with the drug or its solution is especially acute in the case of chemotherapeutic drugs or for self-administration by users in their domiciles.